Remove nondeterminism in test_distribution_generic (#454)

test/test_distribution_generic.py

@@ -2,7 +2,7 @@
 # SPDX-License-Identifier: Apache-2.0
 
 import re
-from collections import OrderedDict
+from collections import OrderedDict, namedtuple
 from importlib import import_module
 
 import numpy as np
@@ -89,17 +89,16 @@ def __init__(self, raw_dist, raw_params, expected_value_domain, xfail_reason="")
         self.raw_dist = re.sub(r"\s+", " ", raw_dist.strip())
         self.raw_params = raw_params
         self.expected_value_domain = expected_value_domain
-        for name, raw_param in self.raw_params:
-            if get_backend() != "numpy":
-                # we need direct access to these tensors for gradient tests
-                setattr(self, name, eval(raw_param))
         TEST_CASES.append(
             self if not xfail_reason else xfail_param(self, reason=xfail_reason)
         )
 
     def get_dist(self):
         dist = backend_dist  # noqa: F841
-        case = self  # noqa: F841
+        Case = namedtuple("Case", tuple(name for name, _ in self.raw_params))
+        case = Case(  # noqa: F841
+            **{name: eval(raw_param) for name, raw_param in self.raw_params}
+        )
         with xfail_if_not_found():
             return eval(self.raw_dist)